<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>背景</title>
    <style>
      .main {
      }
    </style>
</head>
<body>
  <div>后台</div>
  <script type="text/javascript" src="js/background.js"></script>
</body>
</html>
